The present invention relates to a hearing aid system and in particular to a receiver system used in the hearing aid system.
A wide variety of hearing aid units are known in the art. In some units, the receiver is positioned within the ear canal in such a way that it creates an occlusion effect. Further, the receiver is encased within the body of the hearing aid. In most cases whether the hearing aid is fitted in the ear, as a custom made instrument, or as an instrument which is placed behind the ear, an occlusion problem exists. This often is a cause of rejection of the amplification due to patient's discomfort with their own voice. This occlusion effect is associated with the sensation of feeling that the patient's head is “at the bottom of the barrel” with the patient's own voice becoming intolerably loud. Placing an earmold or a shell of a custom made hearing aid can produce an additional low frequency amplification of the patient's own voice up to 20 to 30 dB. This can, therefore, be responsible for a four times perceived loudness increase in the patient's own voice. In order to eliminate the occlusion effect, an open ear canal amplification is applied. However, the acoustics of an open ear fitting increase the risk of acoustic feedback prohibiting in most instances to achieve a peak gain of more than 30 dB.
Thus, there is a need for an improved hearing aid system which avoids the occlusion effect and which also avoids feedback, especially during high frequency amplification.